1.
A(n) _____ is a compound formed when the negative ions from an acid combine with the positive ions to form a base.
Correct Answer
D. Salt
Explanation
When the negative ions from an acid combine with the positive ions, they form a compound called a salt. This process is known as neutralization, where the acidic and basic properties cancel each other out. Therefore, the correct answer is salt.
2.
_____ are solutions containing ions that react with acids or bases to minimize their effects.
Correct Answer
A. Buffers
Explanation
Buffers are solutions containing ions that react with acids or bases to minimize their effects. When an acid or base is added to a buffer solution, the buffer components react with the added ions, preventing a large change in pH. This is because buffers are made up of a weak acid and its conjugate base or a weak base and its conjugate acid. The weak acid/base can donate or accept protons, effectively neutralizing the added acid or base and maintaining the pH of the solution within a relatively narrow range.
3.
Which of the following bases can be ingested safely?
Correct Answer
A. Aluminum hydroxide
Explanation
Aluminum hydroxide can be ingested safely because it is commonly used as an antacid to relieve symptoms of heartburn, indigestion, and upset stomach. It works by neutralizing excess stomach acid, providing relief without causing harm to the body. On the other hand, sodium hydroxide, calcium hydroxide, and ammonia are not safe to ingest as they are highly caustic and can cause severe damage to the digestive system if ingested.
4.
In chemical equations describing ionization, what do double arrows pointing in opposite directions indicate?
Correct Answer
B. The ionization reaction is incomplete.
Explanation
The double arrows pointing in opposite directions in a chemical equation indicate that the ionization reaction is incomplete. This means that only a portion of the reactants have been converted into products, and there is still some remaining reactant present. It suggests that the reaction can proceed in both forward and reverse directions, with the equilibrium lying towards the side of the reactants.
5.
Which two terms refer to the amount of acid or base dissolved in solution?
Correct Answer
C. Dilute and concentrated
Explanation
The terms "dilute" and "concentrated" refer to the amount of acid or base dissolved in a solution. A dilute solution contains a small amount of acid or base dissolved in a larger amount of solvent, resulting in a lower concentration. On the other hand, a concentrated solution contains a large amount of acid or base dissolved in a smaller amount of solvent, resulting in a higher concentration.
6.
Which two groups does a soap molecule contain?
Correct Answer
C. Nonpolar carbon chain and salt of a carboxylic acid
Explanation
A soap molecule is composed of a nonpolar carbon chain and a salt of a carboxylic acid. The nonpolar carbon chain is hydrophobic, meaning it repels water, while the salt of a carboxylic acid is hydrophilic, meaning it attracts water. This unique structure allows soap molecules to interact with both water and oil, making them effective at removing dirt and grease from surfaces.
7.
Which of the following substances contains a base?
Correct Answer
C. Fertilizer
Explanation
Fertilizer contains a base because it is typically made up of various compounds that release hydroxide ions (OH-) when dissolved in water. These hydroxide ions are characteristic of bases and can neutralize acids. In contrast, aspirin, vinegar, and lemon juice are all acidic substances. Aspirin is a weak acid, vinegar contains acetic acid, and lemon juice contains citric acid. Therefore, fertilizer is the only substance among the options that contains a base.
8.
A(n) ______ is a substance that produce hydrogen ions in solution.
Correct Answer
D. Acid
Explanation
An acid is a substance that produces hydrogen ions in a solution. When an acid is dissolved in water, it releases hydrogen ions (H+) which can then react with other substances. Acids are known for their sour taste, ability to corrode metals, and ability to turn blue litmus paper red. Some common examples of acids include hydrochloric acid, sulfuric acid, and acetic acid.
9.
What is a disadvantage of adding phosphates to detergents?
Correct Answer
D. pHospHates can cause overgrowth of algae in waterways.
Explanation
Adding phosphates to detergents can lead to the overgrowth of algae in waterways. When these detergents are washed down drains and into water sources, the phosphates act as a nutrient for algae, causing them to multiply rapidly. This excessive growth of algae can disrupt the balance of aquatic ecosystems, deplete oxygen levels in the water, and harm fish and other aquatic organisms. It can also lead to the formation of harmful algal blooms, which can release toxins into the water and pose a threat to human health. Therefore, the presence of phosphates in detergents is a disadvantage due to its negative impact on waterways.
10.
_____ are organic salts.
Correct Answer
C. Soaps
Explanation
Soaps are organic salts because they are formed through the reaction of a fatty acid with a base, usually sodium hydroxide or potassium hydroxide. This reaction results in the formation of a salt called a soap, which consists of a long hydrocarbon chain (from the fatty acid) and a polar head (from the base). Soaps are commonly used for cleaning purposes due to their ability to dissolve dirt and oils in water.